2023, Vol. 13, No. 1, 147 – 156 http://dx.doi.org/10.11594/jtls.13.01.15
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Research Article
Antioxidant Activity, Total Phenolic Content, and Nutrient Composition of Chayote Shoot (Sechium edule, Jacq. Swartz) from Kundasang, Sabah
Amir Husni Mohd Shariff 1, Nurrelyssa Azwa Hainusa 1, Nurul Huda1 *, Mona Zakaria 2, Saeed Ullah 3, Fahrul Huyop 3, Roswanira Abdul Wahab 4
1 Faculty of Food Science and Nutrition, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Malaysia
2 Centre for Language and Pre-University Academic Development, International Islamic University (UIAM), Kuantan Campus, 25200, Pahang, Malaysia
3 Department of Biosciences, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Jo- hor, Malaysia.
4 Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor Bahru, Ma- laysia
Article history:
Submission April 2022 Revised April 2022 Accepted July 2022
ABSTRACT
The chayote (Sechium edule) plant is believed to have significant nutritional im- portance due to its medicinal functions. It has been widely cultivated in Kundasang, Sabah for vegetable consumption. This study was carried out to determine the health benefits of this vegetable, especially the upper 3-foot of the shoot portion, in terms of antioxidant activity, total phenolic content and nutrient composition. It was divided equally into three parts, each a foot long and classified as: upper tier, middle tier and lower tier and amongst them, which tier gives rise to the best health benefits or will the traditional consumption of the whole 3-foot shoot be better for overall health well- being. DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) and Folin Ciocalteu test were used to determine antioxidant activity and Total Phenolic Content (TPC), respectively.
The results showed that the upper tier of shoot parts had the highest value for antiox- idant activity, with the lowest of IC50 value (245.12 ± 9.24 μg/ml). The lower part of the plant also shows the highest value for TPC with a value of 355.66 ± 5.84 mg/g GAE. Minerals, Ca, Mg, P, Mo, Fe and Al were the highest value in the middle tier portion. The proximate analyses showed that the upper tier of the shoot has the highest fat, crude protein, and carbohydrate contents. Crude ash has the highest value in the middle tier part. On the other hand, the moisture content and the crude fiber were high at the lower tier of the shoot portion. The upper tier of the shoot is recommended to be consumed for health benefits because it is high in antioxidant activity and proxi- mate content and also rich in minerals. However, the traditional practice is to consume the whole 3-foot long of this vegetable is very welcome.
Keywords: Antioxidants, Chayote, Minerals, Proximate Analyses, Total Phenolic Content
*Corresponding author:
E-mail: [email protected]
Introduction
Sechium edule (Jacq.) Swartz (Cucurbitaceae), also known as chayote, is an herbaceous plant originally native to Central America [1], a versa- tile vegetable with edible leaves, fruits, shoots, stems, and roots [2]. This plant is widely culti- vated worldwide in Mexico, Africa, Brazil, China, Malaysia, India, and Thailand [3]. Chayote is called cidrayote, chayote, chiote, Cho-Cho, choko,
chow-chow, christophene, custard, hayatouri, hu- isquil, squash mango, mirliton, sayote, vegetable pear, and xuxu depending on some areas where it is planted [2, 4]. Chayote plants are herbaceous plants, monoecious, strong, and energetic creepers. It grows from a single, thick root, which produces roots rooted. Its stems are angular-corru- gated and thickened to the base and woody, while
there are many thin and firm branches at the top.
The stem of this plant can reach 30 to 50 feet (9 to 15 m) in one-year [5]. Leaves have grooved peti- oles with a length of 8-15 cm. The size of the cha- yote leaf grows from the shoots to the bottom of the plant. Like almost all Cucurbitaceae, chayote plants develop tendrils for support [6]. Although adult green fruit is mainly eaten, other parts of the plant are also found to be eaten in young sprout and roots sections that can provide essential nutri- ent sources [7]. Researchers report that pharmaco- logical studies confirm that leaves, fruits, and cha- yote seeds exhibit diuretic, antihypertensive, car- diovascular, and anti-inflammatory properties [6].
This plant is also reported to contain antibacterial [6–10] and antiepileptic activity [11]. Referring to the anti-cardiovascular properties of chayote, pre- vious studies have found that flavonoids in shoots reduce serum lipid and cholesterol content and prevent atherosclerosis [9]. In addition, the intake of leaves and fruits of chayote plants has been found to dissolve kidney stones and other renal diseases and as a cure for lung disease due to its diuretic properties [12]. This crop is grown in many countries like China, India, and Madagascar [13]. The utilization of chayote as functional food has been previously suggested because of the content of flavonoids and their antioxidant activity [14]. The use of leaves and chayote seeds in a daily diet can lower blood pressure and dissolve the calcification of the urine [15].
This study is to evaluate which part of the cha- yote shoots (3-foot long, which is divided equally into three equal sections): the top tier or the middle tier, or the lower tier has the superior content of antioxidants, total phenolic compounds, and nutri- ents that will contribute to the maximum impact on health well-being and indeed the choice for consumption. If proven potent, this vegetable will be able to replace synthetic antioxidants in the food processing industry to some extent, which has been documented to have an adverse effect on humans [16]. A few synthetic antioxidants were approved in the food industry due to their toxicity and carcinogenicity properties [17]. This study ex- amined chayote shoots from different extraction solvents. Natural antioxidants are said to be much safer than synthetic ones, especially in the food and medical industry. Therefore, the phytochemi- cal analysis and antioxidant profile of chayote can provide an important tool for improving the value of the crop as a functional food [18].
Material and Methods Sample Preparation
The plants were derived from the highland area of Cinta Mata Farm in Kampung Mesilau Kundasang, Ranau Sabah. The 3 feet long (0.93 m) chayote plant measuring from the tip of the shoot to the lower part of the plant was analysed for this study (Figure 1). A total of 100 randomly composite samples were harvested from the open field, measuring 100 m x 200 m in size. The sam- ples were wrapped up in brown paper and returned to UMS laboratory for further analysis. The plant parts were weighed and washed using distilled wa- ter to remove dust, if any. Subsequently, the plant was dried for a while in the open air of the labora- tory space.
The 100 pieces of the 3 feet (0.93 m) plant stock were then cut into three (3) sections: top tier shoot, middle tier shoot and lower tier, each a foot
long (0.31 m). Each composite section of the plant stock has a total of 100 samples. Each composite section is then chopped into small pieces (1-2 cm in size) to facilitate and accelerate the drying pro- cess, by increasing the surface area. The samples were dried using the dryer cabinet for 72 hours at 40-50°C and blended using an electronic blender into powder form. Subsequently, samples were stored in a vacuum backpack and stored at room temperature until extraction to determine the anti- oxidant assay and total phenolic content (TPC). In addition, the sample will be used to determine the nutrient content and proximate analyses
Sample Extraction
Determination of antioxidant and TPC was performed by taking 50 g of each sample blended in powder form and mixed with 1L ethanol (80%) Figure 1. Chayote Shoot with tendrils, leaves, and
stem together [18].
at room temperature (25 °C) for 48 hours. Then, the mixture is filtered using the Whatman No.1 fil- ter paper, and the solvent is removed under vac- uum at 40°C using a rotating evaporator. After that, the extracts are stored in a vacuum packing bag. The extraction must be carried out in a dark environment, and the extracted extracts are stored and refrigerated (-20 °C).
Determination of Antioxidant
The 2,2-diphenyl-1-picryl-hydrazyl (DPPH) method for measuring the activity of free radicals in plants is used with some modifications [19].
DPPH testing is a widely accepted method for as- sessing the antioxidant activity of natural com- pounds. Measurements for the decline in DPPH absorption are the methods for determining anti- radical antioxidant in DPPH dissipation at 517 nm.
The activity of free radicals was calculated as a percentage of the DPPH color changes using the following formula:
D(%) =Ab − As
Ab100 … … … (1)
where, as is the absorption of the solution when the sample extract is added to a certain level, and Ab is the absorption of the DPPH solution. Extrac- tion concentrations provide 50% inhibition (IC50) calculated from the percentage of inhibition against extract concentration.
Preparation of Buffered Water and Bligh-Dyer An approximately 300 ml of double distilled water was transferred into a separating funnel and 2.04 g potassium dihydrogen phosphate (KH2PO4) was added to create a 0.05 M solution. The pH was adjusted to pH 7.2 by the addition of sodium hy- droxide (NaOH) pellets and the mixture was ex- tracted with 3 x 50 ml dichloromethane (DCM).
The Bligh-Dyer solvent mixture was made up us- ing buffered water: chloroform: methanol with a ratio of 4:5:10, respectively.
Determination of Total Phenolic Content (TPC) The total phenolic content is calculated using the Folin-Ciocalteu method [20]. A 1 mg sample was dissolved first with 1 ml of methanol and then mixed with 5 ml of Folin-Ciocalteu reagent (which was dissolved ten times with water). After 2-5 minutes, the following sample was mixed with a 7.5% sodium carbonate (Na2CO3) solution of 5 ml into the test tube. The mix was left for 20 minutes
in the dark at 25°C completing the reaction before measuring absorbance using UV-Vis Spectropho- tometer at A765nm. Gallic acid was used as stand- ard compared with the standard acid curve, i.e., Galic Acid Equivalents (mg/g GAE). A 1 mg dis- solved acid in distilled water was used to provide standard curves. The values expressed in mg/g ex- tract of garlic equivalent (GAE) acid. The blank reagent used is 1 ml of methanol, 5 ml of Folin- Ciocalteu reagent, and 5 ml of sodium carbonate (Na2CO3) (7.5%). The total phenolic content was calculated based on the following equation:
C(GAE) = c ×V
M… … … (2)
C = total phenolic content, mg/g plant ex- tract, in GAE;
c = galic acid concentration from calibra- tion, mg/mL;
V = volume extract, mL;
m = weight of plant extract, mg
Determination of Mineral Content
Analysis of calcium (Ca), magnesium (Mg), phosphorus (P), sodium (Na), potassium (P), sele- nium (S), copper (Cu), zinc (Zn), molybdenum (Mo), iron (Fe) and aluminium (Al) were per- formed [21]. A 1 g of the prepared sample was in- serted into a crucible and made ashes at 500 °C for two hours in the furnace and then left cool. Ten, drops of water were added, followed by 3 - 4 mL of nitric acid. The residual nitric acid was left to evaporate on a Bunsen burner at temperatures of about 100 - 120 °C. The crucible was then put into the furnace to continue ashing at 500 °C for an hour. The crucible was left cool in the desiccator.
The resulting ash was dissolved into 10 mL of hy- drochloric acid and then transferred to a volumet- ric flask and diluted with distilled water. Then, the solution was filtered using Whatman No. 1. The macro and micro-mineral elements were deter- mined by using Mass-Spectrophotometry (ICP- MS).
Proximate Analyses
The nutrient composition of the sample was determined using AOAC standard [21]. The mois- ture content was measured by drying in the oven for 5 h at 105°C. A 5 g of sample was weighed in the crucible and dried in the oven. The moisture
content was calculated using the following equa- tion,
Moisture content =B − C
B − A× 100 … … … (3)
where, A is the weight of crucible (g), B is the weight of sample with crucible before (g), and C is the weight of sample with crucible after drying.
Kjedahl method was used for the determination of protein content. The Soxhlet method is used to obtain fat content using the Soxhlet (FOSS Sox- texTM 2050) instrument. The crude fiber content in the sample was determined by the FiberBag sys- tem via Fibertherm (Gerhardt Fiberthern, Ger- many). The system produces carbohydrates, pro- teins and fats that can be dissolved from the sam- ple to obtain coarse fiber content. The ash content was determined using ashing method (Mufle Fur- nace, Carbolite ELF11 / 141201, United King- dom) at high temperature of about 550 °C. Carbo- hydrate content was determined by summing all the percentages of crude protein, crude fat, water content, crude ash, and crude fiber content. The sum of values is then deducted with a value of 100% and the minus results obtained are the value of the carbohydrate contents. All experiments
were conducted in three replications. A 300 ml of double distilled water was transferred into a sepa- rating funnel and 2.04 g potassium dihydrogen phosphate (KH2PO4) was added to create a 0.05 M solution. The pH was adjusted to pH 7.2 by the ad- dition of sodium hydroxide (NaOH) pellets and the mixture was extracted with 3 × 50 ml dichloro- methane (DCM).
Statistical Analysis
The results of this study have been reported in means ± standard deviation. The data were ana- lyzed using SPSS version 26.0 and used one-way variance analysis (ANOVA) with a significant dif- ference (P< 0.05). Post-hoc HSD tests (P<0.05) were used to accomplish the analysis.
Results and Discussion
Antioxidant activity of Chayote shoot
In Table 1, the antioxidant activity of the cha- yote shoot is 245.12 ±9.24 µg/ml for the top tier of the shoot (1st foot), whilst the middle tier (2nd foot length) is 255.92 ± 10.79 µg/ml and the lower tier (3rd foot length) is 278.03 ± 7.62 µg/ml based on IC50 value. The lowest value is the indicator of the highest antioxidant activity, which is the top
Table 1. The IC50 value is based on the percentage of antioxidant scavenging activity in the chayote shoot of 3-foot long divided equally into three (3) equal sections of top tier shoot, middle tier shoot, and lower tier shoot, expressed in µg/ml.
Chayote Plant Parts
Chayote Plant Parts
Top Tier Shoot Middle Tier Shoot Lower Tier Shoot IC50 (μg/ml) 245.12 ±9.24 255.92 ± 10.79 278.03 ± 7.62
Figure 2. Percentage of radical scavenging of DPPH in 400μg / ml extracts from chayote shoot of 3-foot long divided equally in three (3) equal section of top, middle and lower tier shoot.
0 10 20 30 40 50 60 70 80 90 100
0 100 200 300 400 500
Antioxidant activity, %
Extract concentration (μg/ml)
tier of the shoot, followed by the mid-tier and the lowest antioxidant is the lower tier of the stem. No significant relationship was noted between the shoot and middle tier, but both differ significantly from the lower tier at P<0.05. However, the upper tier has the superior value over the rest even though a non-significant difference was noted in the middle tier (Table 1).
The percentage of scavenging activity against the extractant concentration is the highest in the upper tier shoot, followed by the middle and lower tiers (Figure 2). The results were lower than those previously reported [14]. The chayote fruits were found to contain slightly higher antioxidant values of 700 µg/ml [13]. The higher amounts of antiox- idants values recorded in the shoots compared to the middle tier and the lower tier could be due to the significant amount of various polyphenol com- pounds, vitamin C, Vitamin A and phenolic acids [22, 23].
The highest total phenolic content (TPC) was in the top tier shoot (355.66 ± 5.84 mg/g GAE), followed by mid-tier (350.38 ± 6.65 mg/g GAE) and the least in the lower tier section (310.73
±6.68 mg/g GAE) (Table 2), with no significant difference noted between the first two, even though the upper shoot has a higher value than the middle shoot. However, the upper and the middle shots differed significantly from the lower shoot section (P<0.05). This TPC result corresponds with the antioxidant activities of the top shoot, middle shoot, and lower shoot (Table 1), where the highest scavenging activity is seen in the upper shoot, followed by the mid and the lowest value in the lower shoot.
The cause of the variation of TPC may also be attributed to factors such as maturity stage, geo- graphic location, climatic environment, harvesting and handling of plants, and storage methods used [24]. Other reported fruit contain a range of TPC values of 60-260 mg/g GAE [27], a value much lower than the content of the Chayote‘s leaves
(Table 2). This suggests that consuming chayote leaves is more beneficial than consuming fruits.
Consuming both is very much welcome, where TPC is an important source of antioxidants, richly found in fruits & vegetables [25].
Mineral contents
It is interesting to note that mineral concentra- tion values such as Ca, Mg and Fe are significantly higher in the fruit compared to the leaves and stems [26]. In a study conducted based on differ- ent plant locations (terrestrial factors), plant age and plant species have been found to influence the plant mineral concentrations [27]. In addition, other causes of variation may also be attributed to factors such as maturity stage, geographic loca- tion, climatic environment, harvesting and han- dling of plants and storage methods used [24]. However, other studies found that Ca, Fe and P minerals are present in both plant leaf and stem [28, 29]. The variation in the minerals con- tent in the leaves and stems can be attributed to terrestrial factors and fertilizers applications [30].
Macronutrient
Macronutrients are required in large quantities by plants and micronutrients are needed in smaller amounts [31]. The lack of any of these elements can inhibit growth and reduce crop yields [32-34].
In Table 3, the top tier shoot recorded the highest amounts of P (239.19 ± 3.77 µg/g), moderate in the middle tier section (206.84 ± 5.12 µg/g) and lowest in the lower tier of the shoot 145.09 ± 0.31 µg/g) and all differ significantly. P is considered as a highly mobile nutrient [26, 35] and is biolog- ically active at the plant growing tips [36]. It is in- teresting to note that Ca is the highest in the lower part of the shoot (135.59 ± 0.98 µg/g) and moder- ate in the middle tier section of the shoot (131.38
± 0.68 µg/g) and lowest in the upper tier shoot (105.79 ± 0.34 µg/g). This is expected since Ca is the least mobile of all nutrients [37, 38] and will Table 2. The phenolic content in the chayote shoots when the 3-foot long is divided equally into three (3) equal
sections, top, middle and lower tier shoot.
Chayote Plant Parts
Chayote Plant Parts
Top Tier Shoot Middle Tier Shoot Lower Tier Shoot Total Phenolic Content (mg/g GAE) 355.66±5.84a 350.38±6.65a 310.73±6.68b Values with different alphabetical letters in the row indicate significant differences at (P<0.05), with n=3.
accumulate in the mature tissue. In comparison with other vegetables, the results of the study show that the chayote plant contains a high value of Ca concentration compared to other vegetable species such as green peppers (Capsicum annuum) and broccoli (Brassica oleracea L. var. Italica), with 8.7 µg/g and 100 µg/g, respectively. However, spinach (Spinacia oleracea) contains 4-fold higher of Ca concentration at 600 µg/g [39].
Therefore, for macronutrients, P is the highest in all the three plant parts with an average of 197.04±3.07 µg/g followed by Ca at 124.25± 1.35 µg/g and Mg 66.07±3.60 µg/g, and the least being Na with a value of 4.03±0.56 µg/g. Antagonistic factors may contribute to the low Mg concentra- tion in the leaves of Chayote, where high Ca con- centration in the soil may suppress the Mg uptake [40]. On the other hand, minerals such as Ca and P are found to exceed the concentration values [28, 41].
Micronutrient
Microminerals in Table 3, such as Cu, Zn, Mo, Fe, and Al are not significant (p ˃0.05) amongst all three plant tiers. However, Cu is the highest found in the upper tier shoot area (0.37 ± 0.04 µg/g) compared to other tier zones. Cu is required in small amounts of 0.05-0.5 µg/g in the growing process between 3-10 µg/g in plant tissue and acts as an enzyme activator and intensifies flavour and colour in vegetables [42]. Cu also participates in numerous physiological functions, for example, as an essential cofactor for many metalloproteins [5].
Zn is almost equal amounts with no significant dif- ference amongst them. This nutrient is important
for chlorophyll and auxin formations and the con- version of starch to sugar [43]. According to Ji et al. [44] translocation mechanisms of minerals may contribute to the high supply factor of Zn towards the lower tier of the shoot. Iron is the highest num- ber of micronutrients found in the leaves of vege- table chayote, dominating most in the mid-tier of the shoot (3.56 ± 0.71 µg/g), followed by the top tier shoot section (2.78 ± 0.4 µg/g) and the lowest in the lower tier of the shoot section with 2.41 ± 0.8 µg/g with no significant difference amongst them. Iron plays a critical role in the plant meta- bolic processes in DNA synthesis, respiration, and photosynthesis and many metabolic pathways are activated by Fe and a prosthetic group constituent of many enzymes [45]. Iron can be toxic if it is on high levels due to the tendency to form hydroxyl radicals that can damage the cell's mass [46]. The concentration of other elements, such as the pres- ence of low Mg can also affect the concentration of Fe in the leaves due to their negative syngenetic effect [40]. The pH of the growing medium is crit- ical in the availability of Fe for plant uptake.
Al is almost equal in all three tiers with no sig- nificant difference with each other (P<0.05). The Al in soils of the tropics, is in low pH values of less than 5.5 [47]. However, the Kundasang area is mostly metamorphic derived soils with soil pH of between 5.0 to 5.5 and are not expected to con- tain high Al concentrations as reflected in the fo- liar analyses [48]. Mo is almost uniform in all the three tiers of the shoots with no-significance dif- ference to each other (P<0.05). This nutrient is re- quired in a small amount for normal plant devel- opment and the range in most plant tissues is be- tween 0.3-1.5 µg/g and those recorded in the Table 3. Minerals content of chayote shoot of 3-foot long divided equally in three (3) equal sections of top,
middle and lower tier shoot, expressed in µg/g
Chayote Plant Parts
Macronutrient Micronutrient Top Tier Shoot Middle Tier Shoot Lower Tier Shoot
Ca 105.79 ± 0.34a 131.38 ± 0.68b 135.59± 0.98b
Mg 59.48 ± 1.36a 79.04 ± 6.76b 59.68 ± 2.69a
P 239.19 ± 3.77a 206.84± 5.12b 145.09± 0.31c
Na 4.76 ± 0.48ac 3.33 ± 0.56b 4.01 ± 0.63bc Cu 0.37 ± 0.04a 0.35 ± 0.05a 0.28 ± 0.06a Zn 1.45 ± 0.08a 1.41 ± 0.23a 1.66 ± 1.04a Mo 0.16 ± 0.031a 0.18± 0.02a 0.15 ± 0.03a
Fe 2.78 ± 0.44a 3.56 ± 0.71a 2.41 ± 0.77a Al 0.79 ± 0.07a 0.89 ±.01a 0.83 ± 0.01a
Values are expressed as the mean ± standard error of the mean (SE); with n = 3; Letters represent significant differences at p < 0.05 using ANOVA and Tukey's HSD test.
Table 4. Proximate concentrations (%) of chayote shoot, of 3-foot long divided equally in three (3) equal sections of top, middle and lower tier shoot.
Proximate analyses (%) Chayote Plant Parts
Top Tier Shoot Middle Tier Shoot Lower Tier Shoot
Moisture 89.48 ± 0.06a 90.29 ± 0.25a 90.55 ± 0.63a
Fat 0.21 ± 0.02c 0.19 ± 0.01bc 0.14 ± 0.02a
Crude protein 3.33 ± 0.29a 3.15 ± 0.20a 3.01 ± 0.24a
Crude fibre 1.35 ± 0.08a 1.87 ± 0.04bc 2.04 ± 0.14c
Ash 1.27 ± 0.02a 1.17 ± 0.05a 1.15 ± 0.12a
Carbohydrate 4.36 ± 0.24b 3.20 ± 0.19a 3.12 ± 0.13a
Values are expressed as the mean ± standard error of the mean (SE); with n = 3; Letters represent significant difference at p < 0.05 using ANOVA and Tukey's HSD test.
growing medium range between 0.01-0.20 µg/g [43]. The mineral movement is said to occur from the older leaves to the younger parts of the leaf and therefore, the difference is not noticeable between the three tiers of shoots [36, 38].
Proximate analyses
The chemical composition of moisture, fat, crude protein, ash, and carbohydrates contents was analysed as shown in Table 4. The top tier of the shoot of chayote is the richest in all the investi- gated proximate components, with the middle tier showing the same content and the lowest being the lower tier, with the exception of crude fibre, ex- hibiting the opposite trend and moisture content as well. The moisture content exhibits a descending trend with 89.48 ± 0.06 % in the upper tier, the mid-tier with 90.29 ± 0.25 %, and the lower tier having 90.55 ± 0.63 % and all values were not- significant to each other, indicating the distribu- tion of water is almost uniform throughout the 3- foot shoot of the chayote. Furthermore, the loca- tion in Kundasang is considered an elevated site with relatively high humidity [49].
Fat content is the highest in the upper tier (0.21
± 0.02 %), followed by 0.19 ± 0.01 % at the mid- tier and 0.14 ± 0.02 % in the lower tier, with no significant difference. Different fat concentrations in many plants may be due to plant metabolism [41]. The crude protein content, with the top tier, has the higher value (3.33 ± 0.29%), followed by the mid-tier (3.15 ± 0.20 %) and lower tier (3.01 ± 0.24 %). All were non-significant to each another, indicating a uniformity in the protein content of the chayote shoot. Other studies reported higher protein content in the stem and not in the leaves of chayote [4]. The crude fibre was observed with the highest content in the lowest tier zone (2.04 ± 0.14%) but not in other parts of the zone. This re- sult is very much anticipated since the lower zone is the most mature part of the shoot, followed by the mid-tier section, and the youngest shall be the tip of the shoot (Table 4). According to Vieira et al. [16] higher crude fiber content is found in the leaves than in the stem, which is contradicted in this current study. The different content of crude fibre may be attributed to the differences in plant species, plant maturity, seasonal variation, ferti- lizer, or analytical techniques [19]. In contrast, Cucurbita pepo plants also derived from the Cu- curbitaceae family found in sub-Saharan Africa
show lower levels of crude fibre content compared to the chayote plants [50].
The content of crude ash is higher in the upper tier of the shoot (1.27 ± 0.02 %), whereas the mid- tier (1.17 ± 0.05 %) and lower tier sections (1.15
± 0.12 %) showed no significant difference. The previous study reported that chayote ash content in the leaf and stem was in the range of 0.90-1.20 % which was close to the current study [4].
The carbohydrate, mostly the sugar fractions, is superior in concentrations in the upper tier (4.36
± 0.24 %), compared to the mid-tier section (3.20
± 0.19 %) and the lower tier section (3.12 ± 0.13
%). The finding of the different patterns for carbo- hydrate content in different parts of the chayote shoot is supported by the work of Ismail et al. [51]
on Strobilanthes crispus. According to Schiltz et al. [52], the concentration of carbohydrates in- creases throughout plant growth with the higher carbohydrate content at the higher level of plant development.
Conclusion
The best plant part to be consumed in the up- per tier of the shoot portion, a foot from the tip down. This top portion of the plant part is rich in antioxidant and proximate contents compared to the middle and the lower tiers section. These have been seen from the TPC (mg/g GAE) and proxi- mate readings as well. This makes the first foot portion of Chayote shoot the most prolific and highly nutritious part of the plant that highly rich in nutrients.
Acknowledgment
The authors are grateful to the Universiti Ma- laysia Sabah, International Islamic University Ma- laysia and Universiti Teknologi Malaysia for the support to conduct research in the area of Science and Technology.
References
1. Ángel-Coronel OAD, León-García E, Vela-Gutiérrez G et al. (2018) Lipoxygenase activity associated to fruit rip- ening and senescence in chayote (Sechium edule Jacq.
Sw. cv. “virens levis”). Journal of Food Biochemistry 42 (1): 12438. doi: 10.1111/jfbc.12438.
2. Lim TK (2012) Edible medicinal and non-medicinal plants. Vol 2. Fruits, Springer Dordrecht. doi:
10.1007/978-94-007-1764-0.
3. Islam S, Kumar A, Dash KK, Alom S (2018) Physico- chemical analysis and nutritional properties of fresh, osmo-dehydrated and dried chayote (Sechium edule L.).
Journal of Postharvest Technology 6 (2): 49-56.
4. Saade RL (1996) Chayote, Sechium edule (Jacq.) Sw.
Promoting the conservation and use of underutilized and
neglected crops. Rome, Institute of Plant Genetics and Crop Plant Research, Gatersleben/International Plant Ge- netic Resources Institute.
5. Yruela I (2009) Copper in plants: acquisition, transport and interactions. Functional Plant Biology 36: 409- 430. doi: 10.1071/FP08288.
6. Noumedem JA, Mihasan M, Lacmata ST et al. (2013) An- tibacterial activities of the methanol extracts of ten Cam- eroonian vegetables against Gram-negative multidrug-re- sistant bacteria. BMC Complementary and Alternative Medicine 3 (1): 1-9. doi: 10.1186/1472-6882-13-26.
7. Podsędek A, Redzynia M, Klewicka E, Koziołkiewicz (2014) Matrix effects on the stability and antioxidant ac- tivity of red cabbage anthocyanins under simulated gas- trointestinal digestion. Biomed Research International 2014: 1-12 (365738). doi: 10.1155/2014/365738.
8. Diré GF, Almeida MC, Coura MF et al. (2007) Effects of a chayotte (Sechium edule) extract (macerated) on the bi- ochemistry of blood of Wistar rats and on the action against the stannous chloride effect. Pakistan Journal of Biological Sciences 10 (5): 823-827. doi:
10.3923/pjbs.2007.823.827.
9. Yang MY, Chan KC, Lee YJ et al. (2015) Sechium edule Shoot Extracts and Active Components Improve Obesity and a Fatty Liver That Involved Reducing Hepatic Lipo- genesis and Adipogenesis in High-Fat-Diet-Fed Rats.
Journal of Agricultural and Food Chemistry 63(18):
4587–4596. doi: 10.1021/acs.jafc.5b00346.
10. Morales P, Carvalho AM, Sánchez-Mata MC et al. (2012) Tocopherol composition and antioxidant activity of Span- ish wild vegetables. Genetic Resources and Crop Evolu- tion 59: 851–863. doi: 10.1007/s10722-011-9726-1.
11. Firdous SM, Sravanthi KA, Debnath RA, Neeraja KA, (2012) Protective effect of ethanolic extract and its ethylacetate and n-butanol fractions of Sechium edule fruits against carbon tetrachloride induced hepatic injury in rats. International Journal of Pharmacy and Pharma- ceutical Sciences 4 (1): 354-359.
12. Cadena-Iñiguez J, Arévalo-Galarza L, Ruiz-Posadas LM, et al. (2006) Quality evaluation and influence of 1-MCP on Sechium edule (Jacq.) Sw. fruit during postharvest.
Postharvest Biology and Technology 40 (2): 170-176.
doi: 10.1016/j.postharvbio.2005.12.013.
13. Loizzo MR, Bonesi M, Menichini F et al. (2016) Antiox- idant and carbohydrate-hydrolysing enzymes potential of Sechium edule (Jacq.) Swartz (Cucurbitaceae) peel, leaves and pulp fresh and processed. Plant Foods for Hu- man Nutrition 71 (4): 381-387. doi: 10.1007/s11130-016- 0571-4.
14. Chao PY, Lin SY, Lin KH et al. (2014) Antioxidant ac- tivity in extracts of 27 indigenous Taiwanese vegetables.
Nutrients 6 (5): 2115-2130. doi: 10.3390/nu6052115.
15. Kumawat BK, Gupta M, Tarachand SY (2012) Free radi- cal scavenging effect of various extracts of leaves of Bal- anite aegyptica (L.) delile by DPPH method. Asian Jour- nal of Plant Science and Research 2 (3): 323-329.
16. Vieira EF, Pinho O, Ferreira Isabel MPLVO, Delerue- Matos C (2019) Chayote (Sechium edule): A review of nutritional composition, bioactivities and potential appli- cations. Food Chemistry 275: 557-568. doi:
10.1016/j.foodchem.2018.09.146.
17. Lobo V, Patil A, Phatak A, Chandra N (2010) Free radi- cals, antioxidants and functional foods: Impact on human
health. Pharmacognosy Reviews 4 (8): 118. doi:
10.4103/2F0973-7847.70902.
18. Chang KA, Ley SL, Lee MY et al. (2021) Determination of nutritional constituents, antioxidant properties, and α- amylase inhibitory activity of Sechium edule (chayote) shoot from different extraction solvents and cooking
methods. LWT 151: 112177. doi:
10.1016/j.lwt.2021.112177.
19. Vukic M.D, Vukovic NL, Djelic GT et al. (2018) Phyto- chemical analysis, antioxidant, antibacterial and cyto- toxic activity of different plant organs of Eryngium ser- bicum L. Industrial Crops and Products 115: 88-97. doi:
10.1016/j.indcrop.2018.02.031.
20. Soobrattee MA, Neergheen VS, Luximon-Ramma A, Aruoma OI, Bahorun T (2005) Phenolics as potential an- tioxidant therapeutic agents: mechanism and actions. Mu- tation Research/Fundamental and Molecular mechanisms of mutagenesis 579 (1-2): 200-213. doi:
10.1016/j.mrfmmm.2005.03.023.
21. AOAC (2000) Official methods of analysis of AOAC. In- ternational 17th edition.
22. Capecka E, Mareczek A, Leja M (2005) Antioxidant ac- tivity of fresh and dry herbs of some Lamiaceae species.
Food Chemistry 93 (2): 223-226. doi: 10.1016/j.food- chem.2004.09.020.
23. Liu J, Wang X, Yong H, Kan J, Jin C (2018) Recent ad- vances in flavonoid-grafted polysaccharides: Synthesis, structural characterization, bioactivities and potential ap- plications. International Journal of Biological Macromol- ecules 116: 1011-1025. doi: 10.1016/j.ijbi- omac.2018.05.149.
24. Van Jaarsveld P, Faber M, Van Heerden I et al. (2014) Nutrient content of eight African leafy vegetables and their potential contribution to dietary reference intakes.
Journal of Food Composition and Analysis 33 (1): 77-84.
doi:10.1016/j.jfca.2013.11.003.
25. Biswas M, Haldar PK, Ghosh AK (2010) Antioxidant and free-radical-scavenging effects of fruits of Dregea volu- bilis. Journal of Natural Science, Biology, and Medicine 1 (1): 29. doi: 10.4103/2F0976-9668.71670.
26. Kudoyarova GR, Vysotskaya LB, Arkhipova TN et al.
(2017) Effect of auxin producing and phosphate solubil- izing bacteria on mobility of soil phosphorus, growth rate, and P acquisition by wheat plants. Acta physiologiae plantarum, 39 (11): 1-8.doi: 10.1007/s11738-017-2556- 9.
27. García-Herrera P, Sánchez-Mata MC, Cámara M et al.
(2014) Nutrient composition of six wild edible Mediter- ranean Asteraceae plants of dietary interest. Journal of Food Composition and Analysis 34 (2): 163-170. doi:
10.1016/j.jfca.2014.02.009.
28. Sriwichai W, Berger J, Picq C, Avallone S (2016) Deter- mining factors of lipophilic micronutrient bioaccessibility in several leafy vegetables. Journal of Agricultural and Food Chemistry 64 (8): 1695-1701.
doi: 10.1021/acs.jafc.5b05364.
29. Lalthansanga J, Samanta AK (2015) Effect of feeding chayote (Sechium edule) meal on growth performance and nutrient utilization in indigenous pig (Zovawk) of Mi- zoram. Veterinary World 8 (7): 918. doi: 10.14202/vet- world.2015.918-923.
30. Shen JP, Zhang LM, Guo JF et al. (2010) Impact of long- term fertilization practices on the abundance and compo- sition of soil bacterial communities in Northeast China.
Applied Soil Ecology 46 (1): 119-124.doi: 10.1016/j.ap- soil.2010.06.015.
31. White PJ, Brown PH (2010) Plant nutrition for sustaina- ble development and global health. Annals of Botany 105 (7): 1073-1080. doi: 10.1093/aob/mcq085.
32. Schütz L, Gattinger A, Meier M et al. (2018) Improving crop yield and nutrient use efficiency via biofertilization a global meta-analysis. Frontiers in Plant Science 12 (8):
2204. doi: 10.3389/fpls.2017.02204.
33. Fageria NK, Baligar VC, Li YC (2008) The role of nutri- ent efficient plants in improving crop yields in the twenty first century. Journal of plant nutrition 31 (6): 1121-1157.
doi: 10.1080/01904160802116068.
34. Reich M (2017) The significance of nutrient interactions for crop yield and nutrient use efficiency. In Plant macro- nutrient use efficiency. Elsevier: Amsterdam, The Neth- erlands. 65-82.
35. Arkhipova T, Galimsyanova N, Kuzmina L, Vysotskaya L et al. (2019) Effect of seed bacterization with plant growth-promoting bacteria on wheat productivity and phosphorus mobility in the rhizosphere. Plant, Soil and Environment 65 (6): 313-319. doi: 10.17221/752/2018- PSE.
36. Amir HM, Chik SW, Yaacob A, Mohd GH (1993) Which canopy tier should be sampled to determine the fertility (nutritional) status of Acacia mangium on BRIS soils?
Journal of Tropical Forest Science: 48-55.
37. Fageria VD (2001) Nutrient interactions in crop plants.
Journal of plant nutrition 24 (8): 1269-1290. doi:
10.1081/PLN-100106981.
38. Amir SHM, Miller HG (1990) Shorea leprosula as an in- dicator species for site fertility evaluation in dipterocarp forests of Peninsular Malaysia. Journal of Tropical Forest Science: 101-110.
39. Martínez-Ballesta MC, Dominguez-Perles R, Moreno DA et al. (2010) Minerals in plant food: effect of agricul- tural practices and role in human health. A review. Agron- omy for sustainable development 30 (2): 295-309. doi:
10.1021/jf00102a007.
40. Jayaganesh S, Venkatesan S (2010) Impact of magnesium sulphate on biochemical and quality. Am. J. Food Techn, 5: 31-39. doi: 10.3923/ajft.2010.31.39.
41. Rao KS, Dominic R, Singh K et al. (1990) Lipid, fatty acid, amino acid, and mineral compositions of five edible
plant leaves. Journal of Agricultural and Food Chemistry, 38 (12): 2137-2139. doi: 10.1021/jf00102a007.
42. Muhammad I, Altaf A, Ansari MKA et al. (2015) Improv- ing the phytoextraction capacity of plants to scavenge metal (loid)-contaminated sites. Environmental Reviews 23 (1): 44-65. doi: 10.1139/er-2014-0043.
43. Pandey GK, Mahiwal S (2020) Emerging Roles of Potas- sium in Plants. In: Role of Potassium in Plant Culture. Ed.
Pandey GK. Mahiwal S Springer Cham 69-74. doi:
10.1007/978-3-030-45953-6.
44. Marschner H (2011) Marschner's mineral nutrition of higher plants. 4th Edition. Academic press. doi:
10.1016/C2009-0-63043-9.
45. Rout GR, Sahoo S (2015) Role of iron in plant growth and metabolism. Reviews in Agricultural Science 3: 1-24.
doi: 10.7831/ras.3.1.
46. Briat JF, Dubos C, Gaymard F (2015) Iron nutrition, bio- mass production, and plant product quality. Trends in Plant Science, 20 (1): 33-40. doi:
10.1016/j.tplants.2014.07.005.
47. Silva S (2012) Aluminium toxicity targets in plants. Jour- nal of Botany. doi: 10.1155/2012/219462.
48. Hall R, Cottam M, Suggate S, Tongkul F, Sperber C, Batt G (2009) The geology of mount kinabalu. Malaysia, Sa- bah Parks: Kota Kinabalu.
49. Mortensen LM, Gislerod HR (2000) Effect of air humid- ity on growth, keeping quality, water relations, and nutri- ent content of cut roses. Gartenbauwissenschaft 65 (1):
40-44.
50. Odhav B, Beekrum S, Akula US, Baijnath H (2007) Pre- liminary assessment of nutritional value of traditional leafy vegetables in KwaZulu-Natal, South Africa. Journal of food composition and analysis 20 (5): 430-435. doi:
10.1016/j.jfca.2006.04.015.
51. Ismail M, Manickam E, Danial AM, Rahmat A, Yahaya A (2000) Chemical composition and antioxidant activity of Strobilanthes crispus leaf extract. Journal of Nutitional Biochemistry 11: 536-542 doi: 10.1016/S0955- 2863(00)00108-X.
52. Schiltz S, Munier-Jolain N, Jeudy C et al. (2005) Dynam- ics of exogenous nitrogen partitioning and nitrogen remo- bilization from vegetative organs in pea revealed by 15N in vivo labeling throughout seed filling. Plant Physiology, 137 (4): 1463-1473. doi: 10.1104/pp.104.056713.
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